Corythomantis greeningi

Corythomantis greeningi, occasionally called Greening's frog,[2] is a venomous[3] frog species in the family Hylidae endemic to eastern Brazil,[4] where it lives in Caatinga habitat. It is usually situated on vegetation, including in bromeliads, and on rock outcrops. Breeding occurs in temporary streams. Although suffering from habitat loss, it is not considered threatened by the IUCN.[1] The specific name greeningi was in honour of Linnaeus Greening (1855–1927), an English businessman and naturalist known for his work on arachnids, reptiles and amphibians.[5]

Corythomantis greeningi
Drawing from 1896 species description
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Hylidae
Genus: Corythomantis
Species:
C. greeningi
Binomial name
Corythomantis greeningi
Boulenger, 1896
Synonyms
List
    • Corythomantis schubarti Miranda-Ribeiro, 1937
    • Corythomantis schubarthae Lutz, 1968

Description edit

Female Corythomantis greeningi grow to a length of about 87 mm (3.4 in) while males are slightly smaller at 71 mm (2.8 in). The head is narrow, with bony crests behind the eyes and a long flat snout, armed with small spines. The body is slender, the skin being covered with warts. The legs are also slender and the fingers and toes have well-developed adhesive discs at the tip. The general color is light brown or gray, liberally blotched with red or brown patches; females are generally darker in color than males.[2]

Distribution and habitat edit

Corythomantis greeningi is endemic to northeastern Brazil. Its range extends as far south as the northern part of Minas Gerais state. It inhabits a caatinga ecoregion, a semi-desert vegetation of shrublands and thorn forest.[1] This experiences a short wet season, lasting about three months, and a long hot dry season.[6]

Ecology edit

With a need to keep its skin moist and as a protection against predators, C. greeningi conceals itself in a tree hollow, a rock crevice, a bromeliad or other suitable location. In the laboratory, a female frog used a test tube for a retreat, sealing off the aperture with its head. In their natural habitat, when the rainy season starts and the creeks and channels run with water, male frogs establish territories near the watercourses and call to attract females. Several hundred eggs are laid by the female, attached to a rock in the watercourse.[2]

This frog has evolved certain adaptations to enable it to live in a semi-arid environment. The head is roughened and flat, and the skin of the head is fused to the skull forming a casque; these features are often associated with phragmotic behaviour, in which an animal defends itself in a burrow by using its own body as a barrier. It has adapted its life cycle and method of reproduction to suit its environment.[7] It also has a tough, impermeable skin which helps limit water loss, and a low basal metabolic rate which limits evaporation through its lungs.[8] Unlike poison dart frogs which merely secrete poison from their skin, this species is equipped with skull spines capable of injecting venom into other animals, or human hands, via headbutting, a tactic it shares with Aparasphenodon brunoi.[9][10]

The skin secretions contain a number of low-molecular mass steroids and alkaloids. In the laboratory, these produce a powerful nociceptive (painful) effect and cause oedema in mice cells. The secretions also inhibit cell growth in mouse fibroblasts and melanoma cells. In the wild, these provide a useful arsenal of chemical defences against predation.[11]

Status edit

This frog has a wide range and is a common species with a large total population. The main threats it faces include habitat loss from livestock grazing and crop cultivation, and the occurrence of wildfires. The International Union for Conservation of Nature has rated its conservation status as being of "least concern", because any decrease in population size is likely to be at too slow a rate to justify classifying it in a more threatened category.[1]

References edit

  1. ^ a b c d Diva Borges-Najosa, Gabriel Skuk (2004). "Corythomantis greeningi". IUCN Red List of Threatened Species. 2004: e.T55303A11286222. doi:10.2305/IUCN.UK.2004.RLTS.T55303A11286222.en. Retrieved 16 November 2021.
  2. ^ a b c Halliday, Tim (2016). The Book of Frogs: A Life-Size Guide to Six Hundred Species from Around the World. University of Chicago Press. p. 284. ISBN 978-0-226-18465-4.
  3. ^ Satherley, Dan (2015). "Biologist discovers venomous frog the hard way". Archived from the original on 20 August 2015. Retrieved 7 August 2015.
  4. ^ Frost, Darrel R. (2014). "Corythomantis greeningi Boulenger, 1896". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 5 August 2014.
  5. ^ Beolens, Bo; Watkins, Michael & Grayson, Michael (2009). The Eponym Dictionary of Mammals. JHU Press. p. 84. ISBN 978-0-8018-9533-3.
  6. ^ Lleras, Eduardo. "Caatinga of North-Eastern Brazil". Centres of Plant Diversity. Vol. 3: The Americas. Smithsonian Institution. Archived from the original on 3 March 2016.
  7. ^ Jared Carlos; Antoniazzi, Marta Maria; Katchburian, Eduardo; Toledo, Reynaldo Cicero; Freymüller, Edna (1999). "Some aspects of the natural history of the casque-headed tree frog Corythomantis greeningi Boulenger (Hylidae)". Annales des Sciences Naturelles - Zoologie et Biologie Animale. 20 (3): 105–115. doi:10.1016/S0003-4339(00)86975-0.
  8. ^ Andrade, Denis Vieira; Abe, Augusta Shinya (1997). "Evaporative Water Loss and Oxygen Uptake in Two Casque-Headed Tree Frogs, Apmasphenodon brunei and Corythommtis greeningi (Anura, Hylidae)". Comparative Biochemistry and Physiology Part A: Physiology. 118 (3): 685–689. doi:10.1016/S0300-9629(96)00481-1. PMID 9406443.
  9. ^ "Venomous frogs discovered during painful scientific mishap". CBC News. 2015-08-07. Retrieved 2015-08-07.
  10. ^ Jared, C.; Mailho-Fontana, P. L.; Antoniazzi, M. M.; Mendes, V. A.; Barbaro, K. C.; Rodrigues, M. T.; Brodie, E. D. (2015-08-06). "Venomous Frogs Use Heads as Weapons". Current Biology. 25 (16): 2166–2170. doi:10.1016/j.cub.2015.06.061. PMID 26255851.
  11. ^ Mendes, Vanessa A.; Barbaro, Katia C.; Sciani, Juliana M.; Vassão, Ruth C.; Pimenta, Daniel C.; Jared, Carlos; Antoniazzi, Marta M. (2016). "The cutaneous secretion of the casque-headed tree frog Corythomantis greeningi: Biochemical characterization and some biological effects". Toxicon. 122: 133–141. doi:10.1016/j.toxicon.2016.10.004. PMID 27720761.

External links edit